Mitosis

Here is a video on Mitosis, or how cells divide. This is specific for eukaryotic cells (note: cells that have a membrane enclosed nucleus and organelles. We are made of eukaryotic cells, so are plants).

Please watch the following video before class and bring any questions you may have so we can address them. They both address information differently. Write down any words you may not be familiar with so we can define them in class.

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Biogical Classifications

In the scientific community things must be organized so that they can be better evaluated. We do this in our everyday lives although we may not know it. We can identify a dog as a dog, but we can also differentiate the type of breed. We know dogs and cats are animals but they do not reporduce. Here is where the terms such as species, and viable offspring come into play.

Here is a breakdown of basic classification

Kingdom
Phylum
Class
Order
Family
Genus
Species

Below is an example of how a grizzly bear is classified (source).


We do this with most things in our lives as we look for order. Such as with clothing: sweaters go with sweaters, shorts with shorts, etc. In the example above the Kingdom is Animalia (animals). The Phylum is Chordata, which means chordate, as in, it has a backbone, vertebrae. The class is Mammalia, mammals, which are characterized by mammary glands in females (milk) and hair/fur (these are the easily notible distinctions although there are others). Order Carnivora which means carnivores. Family Ursidae, which groups bears, and then the Genus and Species.

As we go down from Kingdom to Species we get more and more specific. Many of these classifications are done through evolutionary research, DNA analysis, and observations of the various stages of fetal development. In class, we will do a lab which will require us to classify our shoes. Please read over the lab and attached assignement.

Shoe Lab
Classification Resources Please preview this site before the begining of class

Biology

Biology is the study of life, their chemistry, their evolution, and how they are scientifically classified. It is easy to think of biology as all living things, from the microscopic bacteria and viruses that make us sick to the giant elephants that roam Africa.

In its most basic form, all living things are made out of cells.

A Eukaryotic cell is pictured above along with its components. source There are two different types of cells, eukaryotic and prokaryotic. The main difference is that eukaryotic cells (which make up animals, plants, you and me) have a membrane bound nucleus while prokaryotic cells (smaller, bacteria, single celled organisms) do not have a membrane bound nucleus.

But we will discuss cells more indepth at another time. Enjoy viewing some of the links I have added below for you to better understand science. Do not feel overwhelmed, we will go into depth of many of these subjects. You can use these as references if you have questions.

Biology Dictionary  Great resource to look up words you may not be familiar with
Biology 101 General content of basic biology
Biology for Kids Very basic biology (we will get more in depth)

 

The Cell

As we briefly discussed in the previous post, there are two types of cells. There are eukaryotic and prokaryotic cells. We, humans, are all made up of eukaryotic cells. Where prokaryotic cells make up bacteria.

  • Eukarotic cells have a membrane bound nucleus and membrane bound organells (little organs). These are usually much larger than prokaryotes. These make up plants and animals. Note: Plant and animal cells are very different, although they are both eukarotic cells.
  • Prokaryotic cells lack membrane bound nucleus and membrane bound organells. Usually smaller thank eukaryotes. There are different shapes and types of prokaryotic cells. We will discuss those later in the class.

Eukaryotic Animal Cell (source)

Eukaryotic Plant Cell (source)

Prokaryotic Cell (source)

Note that all these cells are different. Take for instance, a plant cell has a very large vacuole which is lacking in animal cells, although they are both eukaryotes. Plant cells also have specialized chloroplast which allows them to make food and energy from the sun. Animal cells do not photosynthesize, thus must eat other organisms to obtain energy.

Prokaryotic cells are much simpler and basic than eukaryotic cells. It is believed that prokaryotes gave rise to eukaryotes after billions of years of evolution. Although prokaryotes are smaller and simpler, do not be deceived. Prokaryotes are very well adapted to their environments and continue to amaze scientists in their abilities.